In a rotary machine that rotate a rotating body such as a fan, a bush connects a shaft of a power source such as a motor and the rotating body such as a fan. The shaft is inserted into a hole provided in the bush, and the rotating body is connected to the outer surface of the bush, for example.
The center of gravity of the bush and the rotating body may be eccentric relative to the shaft. In this case, when the bush and the rotating body rotate, vibration may occur in the rotating body.